Mechanical telephone



(No Model.)

H. '8: E. SELIGMAN.

I MECHANICAL TELEPHONE. flNo. 296,230. Patented Apr. 1, 1884.

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HENRY SELIGMAN AND EMMA SELIGMAN, OF IRVINGTON, NEWV YORK.

MECHANICAL TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 296,230, dated April 1, 1884:.

Application filed July 3, 1883. (No model.)

sounds which attend the direct connection of the line-wire to the listening-diaphragm. WVe find that both these results are obtained by using two diaphragms, one of which is connected directly or by means of a ring to the line-wire, and to the other diaphragm by separate filamentary connections. By placing the two diaphragms on the opposite sides of a hollow globe, the vibrations of the contained air acting laterally on the connecting-filaments have been found ,to materially emphasize the sounds transmitted, and thus add to the delicacy of the instrument. In practice we find that a silk thread is the best filamentary con nection to use between the two diaphragms, and we also find that the strength and accentuation of the sound are improved by using several such connections and securing them to rings resting upon the outside faces of the diaphragms, instead of connecting them directly to the diaphragms themselves. The best result is obtained when one' continuous silk thread is used for all the connections, and is threaded back and forth over the rings at equal intervals and its two ends tied together. By this arrangement all the connections exercise an equal strain upon the diaphragms, and they may all be tightened simultaneously by taking up the thread at any point. The rings are made of metal or wood, or of any other suitable material. The diaphragms are preferably of somestrong woven fabric; but parchment, thin metal, or other material may be used.

Referring to the accompanying drawings, which form a part of this specification, Figure 1 represents a central vertical section of the shell or case. Fig. 2 is a similar view of the telephone complete. Fig. 3 is a perspective view of the diaphragms, showing their relative positions and the connections. Fig. 4 is a detail view of the diaphragm and connections. Fig. 5 represents a modification.

A A are the shells forming the telephonechamber. B B are the two diaphragms fastened separately to the two shells.

G C are the strings or threads connecting the two diaphragms, and D D designate the rings over which the threads 0 0 pass, and which communicate the vibrations between the diaphragms and threads.

E is the line-wire attached to the diaphragm farthest from the speaker or listener, either directly or through the medium of the ring D, as represented in Fig. 4..

The globe is made in halves, to facilitate the hollowing out of the same and the attachment of the diaphragms to the interior. e do not, however, confine ourselves to the globe-shaped chamber, as we may also use the box form represented in Fig. 5,.with double soundingboards, as shown, each of which is provided with a diaphragm, the two diaphragms being connectedaccording to our invention.

It is to be understood that by the term filamentary connection we refer to any threadlike woven or twisted fibers joining the two diaphragms, so as to cause onediaphragm to vibrate in unison with the other, without any stiff metallic connection between them.

WVe are aware that it is not new to construct a mechanical telephone with two diaphragms, said diaphragms being connected by one or more wires; and also that it is not new to employ textile diaphragms, and do not claim such as our invention.

Having thus described our invention, what we claim as new therein, and desire to secure by Letters Patent, is-

1. The combination, in a mechanical telephone, of two diaphragms, a line-wire attached to one of said diaphragms, and filamentary connections between them, as set forth.

'2. The combination, in a mechanical telephone, of an inclosing shell or case, two diaphragms on opposite sides of said shell or casing, filamentary connections between said diaphragms, and a line-wire connected with one of the said diaphragms, for the purpose described.

3. A mechanical telephone formed of a globe-1ikc chamber or case having two diaphragms on opposite sides thereof, one of the diaphragins being connected to the line-wire, and the two diaphragms being connected to each other by one or morethreads, as set forth.

at. A mechanical telephone consisting of two hollow hemispheres, connected as described, each hemisphere being provided with a diaphragm, a thread or threads connecting the two diaphragms, and a 1ine-wire attached to one of the diaphragms, as and for the purpose set forth.

5. The combination, in a mechanical telephone, of two diaphragms, a linewire connected with one of the diaphragms, two rings connected, respectively, to the two diaphragms, and a thread or threads connecting the two rings, substantiallyas and for the purposes set forth.

6. The combination, in a mechanical telephone, of two diaphragms, a line-wire connected with one of the diaphragms, two rings connected, as described, to the two diaphragms, and a single continuous thread pass ing back and forth over the rings, as and for the purpose set forth.

7. The combination, in a mechanical tele phone, of an inclosing case or shell, two diaphragms on opposite sides of the same, rings supported in the center of the diaphragms, filamentary connections between the rings, and a line-wire connected to one of the diaphragms, as set forth.

8. The combination, in a mechanical telephone, of two diaphragms, one or both being non-metallic, filamentary connections between the same, and a line-wire connected to one of the diaphragms, as set forth,

9. The combination, in a mechanical telephone, of two diaphragms, one or both being non-metallic, a ring in the center of each diaphragm, filamentary connections between the rings, and aline-wire connected to one of'the diaphragms, as set forth.

HENRY SELIGMAN'. EMMA SELIGM. 

